Percona

JUNE 4, 2023

In this blog, we’ll provide a comparison between MariaDB vs. MySQL (including Percona Server for MySQL ). Introduction: MariaDB vs. MySQL The goal of this blog post is to evaluate, at a higher level, MariaDB vs. MySQL vs. Percona Server for MySQL side-by-side to better inform the decision making process. What is MariaDB?

Open Source 52

Open Source Servers Storage Scalability 52

Brendan Gregg

SEPTEMBER 25, 2021

These strange questions came to the fore back in 2014 when Netflix was switching services from CentOS Linux to Ubuntu, and I helped debug several weird performance issues including one I'll describe here. A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. How would you _time_ time?

Speed 126

Speed Java AWS Virtualization 126

SQL Server According to Bob

SEPTEMBER 26, 2016

When we released Always On Availability Groups in SQL Server 2012 as a new and powerful way to achieve high availability, hardware environments included NUMA machines with low-end multi-core processors and SATA and SAN drives for storage (some SSDs). As we moved towards SQL Server 2014, the pace of hardware accelerated.

Availability 40

Availability Servers Hardware Benchmarking 40

Percona

JANUARY 14, 2019

What if we use ClickHouse (which is a columnar analytical database) as our main datastore? Well, typically, an analytical database is not a replacement for a transactional or key/value datastore. Although such databases can be very efficient with counts and averages, some queries will be slow or simply non existent. Processed 4.15

Database 40

Database Analytics Blockchain Healthcare 40

SQL Performance

MARCH 17, 2020

Back in 2014, I wrote an article called Performance Tuning the Whole Query Plan. This follow-up post revisits the question for SQL Server 2019, using a larger number of rows. I will be using the 50GB Stack Overflow 2013 database , but any large table with a low number of distinct values would do. Test Environment. BountyAmount.

Servers 86

Servers Tuning Database Efficiency 86

SQL Performance

MAY 1, 2019

The summary rows for heap tables without indexes are the same in both documents (no changes for SQL Server 2016): An explicit TABLOCK hint is not the only way to meet the requirement for table-level locking. The following demo script should be run on a development instance in a new test database set to use the SIMPLE recovery model.

Servers 47

Servers Database Testing Performance 47

High Scalability

JUNE 22, 2018

Charlie Demerjian : what does Intel have planned for their server roadmap? For the same reason the 14/10nm messaging is causing consternation among investors, but the server side is in much worse shape. using them to respond to storage events on s3 or database events or auth events is super easy and powerful. How bad is it?

Internet 113

Internet Internet Scalability Artificial Intelligence 113

SQL Performance

FEBRUARY 22, 2021

I would like to share a couple of recent examples that help illustrate how using deprecated SQL Server features continues to bite us. The system table sys.sysprocesses was replaced way back in SQL Server 2005 by a set of dynamic management views (DMVs), most notably sys.dm_exec_requests , sys.dm_exec_sessions , and sys.dm_exec_connections.

Latency 57

Latency Servers Monitoring Systems 57

SQL Performance

MAY 16, 2019

Without this guarantee, SQL Server might add index rows that are not sorted correctly, which would not be good. For INSERT.SELECT , SQL Server makes its own determination whether to ensure rows are presented to the Clustered Index Insert operator in key order or not. DMLRequestSort Conditions.

Cache 67

Cache Servers Testing Storage 67

SQL Performance

APRIL 8, 2019

These AMD EPYC processors have a number of advantages for SQL Server workloads, as I will explain in this article. This 14nm first-generation AMD EPYC 7551 processor has 32 cores and 64 threads, and it works in one or two-socket servers. Both of these Intel processors are special bespoke models that are not in the Intel ARK database.

Azure 42

Azure Virtualization Storage Benchmarking 42

SQL Server According to Bob

JUNE 3, 2016

SQL Server 2016 ‘It Just Runs Faster’ A bold statement that any SQL Server professional can stand behind with confidence. Try SQL Server 2016 Today. The SQL Server Development team tasked several individuals with scalability improvements and real world testing patterns. – [link]. Follow-up.

Hardware 40

Hardware Software Engineering Transportation Scalability 40

SQL Server According to Bob

JULY 12, 2016

For SQL Server 2008, 2012 and 2014 the trace flag behavior remains the same. For SQL Server 2016 the trace flags are available but the behavior may be altered by the design changes. Trace flag 2549 is used to change how DBCC sees the volume layout of the database. This is behavior is unchanged in SQL Server 2016.

Servers 40

Servers Design Engineering Database 40

SQL Performance

OCTOBER 29, 2019

There are multiple methods to look at poorly performing queries in SQL Server, notably Query Store, Extended Events, and dynamic management views (DMVs). In order to use Query Store and Extended Events, you have to configure them in advance – either enabling Query Store for your database(s), or setting up an XE session and starting it.

C++ 74

C++ Database Servers Tuning 74

Brendan Gregg

NOVEMBER 29, 2017

It's all a bit confusing, and I wrote about this in 2014: [Xen Modes]. When I joined Netflix in 2014, we had begun transitioning from PV to HVM (PVHVM). But not all workloads: some are network bound (proxies) and storage bound (databases). ## 5. This recommendation quickly became out of date. The first was c3.

Virtualization 111

Virtualization AWS Hardware Storage 111

SQL Server According to Bob

JUNE 3, 2016

SQL Server 2016 changes the internal design to (CheckScanner), applying no lock semantics and a design similar to those used with In-Memory Optimized (Hekaton) objects, allowing DBCC operations to scale far better than previous releases. The following chart shows the same 1TB database testing. SQL Server. SQL Server 2014.

Hardware 40

Hardware Cache Servers Software Engineering 40

SQL Performance

JULY 1, 2019

The results are technically non-deterministic since SQL Server could validly return any one of the rows in each group. Nevertheless, if you run this query yourself, you are quite likely to see the same result I do: The execution plan depends on the version of SQL Server used, and does not depend on database compatibility level.

C++ 58

C++ Servers Database Performance 58

Brendan Gregg

SEPTEMBER 25, 2021

These strange questions came to the fore back in 2014 when Netflix was switching services from CentOS Linux to Ubuntu, and I helped debug several weird performance issues including one I'll describe here. A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. How would you _time_ time?

Speed 40

Speed Java AWS Virtualization 40

Brendan Gregg

SEPTEMBER 25, 2021

These strange questions came to the fore back in 2014 when Netflix was switching services from CentOS Linux to Ubuntu, and I helped debug several weird performance issues including one I'll describe here. A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. How would you time time?

Speed 52

Speed Java AWS Virtualization 52

SQL Performance

MARCH 8, 2021

SQL Server 2014 SP2 and later produce runtime (“actual”) execution plans that can include elapsed time and CPU usage for each execution plan operator (see KB3170113 and this blog post by Pedro Lopes). SQL Server makes some timing adjustments in parallel plans to promote consistency, but they are not perfectly implemented.

Servers 95

Servers Tuning Architecture Processing 95

The Morning Paper

AUGUST 27, 2019

I am so pleased to see a database systems paper addressing the concerns of the application developer! A example class of application invariants is database integrity constraints. In a distributed setting with weak consistency, an object is replicated across a set of servers. VLDB’19.

Programming 59

Programming Processing Database Systems 59

Scalegrid

AUGUST 15, 2019

In 2014, we discussed 4 of the top MongoDB GUIs: MongoVue, MongoHub, RockMongo, and Robo 3T (formerly Robomongo), and again in 2016: MongoDB Compass, Robo 3T, Studio 3T, and MongoBooster. Should have an excellent way to measure server and query performance. Import data from RDBMS like MySQL, PostgreSQL, and SQL Server.

Database 40

Database Servers Monitoring Availability 40

SQL Performance

MAY 7, 2019

Back in 2014, I started a series of blog posts here to talk about specific wait types and what they do and don’t mean. I’m going to introduce you to wait statistics and explain how critical they are for troubleshooting workload performance in SQL Server. SQL Server also keeps track of how long the thread has to wait. Scheduling.

Servers 40

Servers Azure Metrics Tuning 40

SQL Performance

APRIL 23, 2019

In SQL Server 2012, grouped (vector) aggregation was able to use parallel batch-mode execution, but only for the partial (per-thread) aggregate. SQL Server 2014 added the ability to perform parallel batch-mode grouped aggregation within a single Hash Match Aggregate operator. Introduction. instructions are available.

Servers 67

Servers Testing Metrics Storage 67

Brendan Gregg

NOVEMBER 28, 2017

It's all a bit confusing, and I wrote about this in 2014: [Xen Modes]. When I joined Netflix in 2014, we had begun transitioning from PV to HVM (PVHVM). But not all workloads: some are network bound (proxies) and storage bound (databases). ## 5. This recommendation quickly became out of date. The first was c3.

Virtualization 40

Virtualization AWS Hardware Storage 40

Alex Russell

MARCH 6, 2021

Devices and networks have evolved too: Alex Russell @slightlylate An update on mobile CPUs and the Performance Inequality Gap: Mid-tier Android devices (~$300) now get the single-core performance of a 2014 iPhone and the multi-core perf of a 2015 iPhone. mid-priced Androids were slightly faster than 2014's iPhone 6.

Performance 124

Performance Network Cache Metrics 124

SQL Performance

MAY 29, 2019

It can be activated from SQL Server 2008 to 2014 inclusive using documented trace flag 610. From SQL Server 2016 onward, FastLoadContext is enabled by default ; the trace flag is not required. For more background, see the Data Performance Loading Guide and the Tiger Team notes on the behaviour changes for SQL Server 2016.

Cache 64

Cache Testing Servers Code 64

All Things Distributed

APRIL 4, 2017

In 2014 and 2015 respectively, AWS opened offices in Stockholm and Espoo, Finland. After migrating, database queries that took six seconds now take three seconds in their AWS infrastructure. This has led us to steadily increase our investment in the Nordics to serve our growing base of enterprise, public sector, and startup customers.

AWS 117

AWS Airlines Latency Games 117

O'Reilly

JULY 25, 2023

To provide some coherence to the music, I decided to use Taylor Swift songs since her discography covers the time span of most papers that I typically read: Her main albums were released in 2006, 2008, 2010, 2012, 2014, 2017, 2019, 2020, and 2022. This choice also inspired me to call my project Swift Papers.

Programming 98

Programming Code Design Benchmarking 98